Apparatus for tracking multiple belts



S p 7, 1954 E. T. LORIG ET AL APPARATUS FOR TRACKING MULTIPLE BELTS Filed June 3. 1955 4 Sheets-Sheet l I VENTOR. v EDWIN T. LORIG AND ALFRED TEPLITZ g HIS ATTORNEY Sept. 7, 1954 E. T. LORIG ET AL 2,688,216

APPARATUS FOR TRACKING MULTIPLE BELTS Filed June 5, 1953 4 Sheets-Sheet 2 INVENTOR. EDWIN T. LORIG AND ALFRED TEPLITZ Mg MK HIS ATTORNEY Sept. 7, 1954 E. T. LORIG El AL 2,688,216

APPARATUS FOR TRACKING MULTIPLE BELTS Filed June 3, 1953 4 Sheets-Sheet 3 INVENTOR. EDWIN T. LORIG AND .ALFRED TEPLITZ HIS ATTORNEY Sept. 7, 1954 E. T. LORIG ET AL 2,688,216

APPARATUS FOR TRACKING MULTIPLE BELTS Filed June- 3, 1953 4 Sheets-Sheet 4 9 a ll. )L A m \fi w 5 g g 8 g .2 g 4/ ii il g: T A" a 5 s 2; 5

g INVENTOR.

EDWIN T. LORIG AND ALFRED TEPLITZ HIS ATTORNEY justed in three different ways.

Patented Sept. 7, 1954 APPARATUS FOR TRACKING MULTIPLE BELTS Edwin T. Lorig and Alfred Teplitz, Pittsburgh,

Pa., assignors to UnitedStates Steel Corporation, a corporation of New Jersey Application June 3, 1953, Serial No. 359,338

This invention relates to apparatus for tracking multiple belts and more particularly to tracking abrasive coated belts used in a belt grinding machine. In such grinding machines it is often desirable to grind articles of considerable width, this requiring the use of wide belts. However, it has been impossible to produce wide belts which will function satisfactorily. One: solution to the problem would appear to be the use of a multiplicity of belts operating in side by .side contact over the same work roll. However, it is impossible to make multiple belts track side by side by the use of conventional belt tracking apparatus since immediately upon contact of adjacent belts one of the belts will climb over the other. The reason for this is that even slight pressure between the two belts will distort the belt fibers in such a way that the slight pressure increases rapidly, thus causing the belts to overlap.

It is therefore an object of our invention to provide apparatus for tracking multiple belts in which the belts are prevented from climbing one on the other.

Another object is to provide an abrading machine having a plurality of endless belts therein.

These and other objects will be more apparent after referring to the following specification and the attached drawings, in which:

Figure 1 is a schematic plan view of one embodiment of our invention;

Figure 2 is a side view of the embodiment of Figure 1;

Figure 3 is a View similar to that of Figure 1 showing a second embodiment of our invention;

Figure 4 is a side view of Figure 3;

Figure 5 is a side view showing details of the embodiment of Figures 3 and 4;

Figure 6 is a view taken on the line VIVI of Figure 5; and

Figure '7 is a fragmentary view taken on the line VII-VII-of Figure 5.

Referring more particularly to Figures 1 and 2 of the drawings, the reference numeral 2 indicates a cylindrical work roll around which passes a pair of abrasive belts B-l and B-2. A self-centering roll 4 of the type shown in the patent to Lorig No. 2,593,157 is mounted adjacent the work roll 2. The roll 4 may also be a self-centering roll of the type shown in the patents to Lorig Nos. 2,592,581 and 2,593,158. A pair of frusto-conical rolls 6 and 8 are mounted in spaced apart relationship with the rolls 2 and 4. Rolls 6 and 8* are mounted with their large diameter ends adjacent each other and may be ad- They may be moved toward and away from the rolls 2 and 4 in order to adjust the tension of the belts 3-! and 3-2; they may be adjusted laterally toward and away from each other; and they may be adjusted angularly with. respect to. the center line of the 8 Claims. (01. 51-435) machine. In other words, the angle l0 may be varied.

The operation of this machine is as follows. The belts 13-! and 13-2 are placed around the rolls and the angularity of the rolls 6 and 8 is adjusted to obtain the desired tracking position of the belts B4 and B-2 thereon. The desired belt tension is obtained by moving the rolls 6 and 8 away from the roll 2. The rolls 6 and 8 are adjusted laterally to position the belts 13-! and B-2 on the roll 2 as shown, that is the edges of the belts will abut each other as they pass over the work roll 2. Thus there will be a continuous belt abrading surface presented to the workpiece W as it is held against the belts. As the belts B-I and B-2 are rotated due to their contact with the driven work roll 2 their adjacent edges will approach each other as they travel from the rolls 6 and 8 toward the self-centering roll 4 and work roll 2 until they contact each other on the work roll 2. In like manner their adjacent edges will diverge from each other as they pass from the work roll 2 toward the rolls 6 and 8. The converging action is due to the centering force of the roll i. If the belt 13-! attempts to climb over belt 134 the relation between the edge tensions in belt B! is disturbed so that its inside edge becomes relatively tighter. This causes belt 3-! to shift away from belt B-2 on the rolls 2 and 6, thereby counteracting the tendency of the belt to climb. I

Figures 3 to '7 disclose a three-belt system which is provided with a work roll l2, a selfcentering roll it or" the same type as roll l, frustoconical rolls Hi and It, and a self-centering roll 2!} of the same type as roll Hi. The rolls IE5 and it are adjusted in the same manner as rolls 6 and 8 and belts B-3 and B-6 pass around the rolls l2, l4, l6 and it in the same manner as the belts B-l and B-2 pass. around the rolls 2, l, 6 and 8. The roll 29 is mounted between thev rolls l5 and I8 and is further removed from the roll Hi. The roll 2@ need only be adjustable toward and away from the rolls l2 and 14 to provide the necessary tension in the belt 13-5. Center belt B-5 tracks in a rigidly straight path under the influence of its individual roll 26 and the roll Hi. The operation of the belts 13-3 and 3-4 over the rolls is controlled in the same manner as in the two-belt system. If one of the outer belts 3-3 or B- l attempts to climb the inner belt B-b it is automatically restored to its correct position by the action described above in discussing the twobelt system. If the center belt 13-5 attempts to climb one of the outer belts the centering action of the roll 14 will distort the fibers of the center belt to cause it to move back to its proper position. In either the two-belt or three-belt system the belts may be of the same or diiierent widths.

As shown in Figures 5, 6 and 7 the rolls i2, I4 [6, l8 and 20 are mounted on a frame 22. A

vertical wall 24 extends upwardly from the base of the frame 22. A web 25 extends horizontally from the wall 24 and supports a second vertical wall 26. A vertical web 21 connects the walls 24 and 26 at one end thereof. The work roll I2 is mounted in bearing brackets 28 detachably secured to the Walls 24 and 26. The roll l2 has a shaft extension 30 on which is mounted a pulley 32 for V-belts 34 which are rotated from a motor 36 through pulley 38. The roll [2 may be removed by first removing the brackets 28 and then sliding the shaft of the roll through the openings 40. The roll H! which consists of two frusto-conical portions rotatably mounted on a fixed bent shaft 42 is also mounted on the vertical walls 24 and 26. The ends of the shaft 42 are mounted in brackets '44 and 46 and are held in place by means of set screws 48. The angular position of the shaft 42 may be varied by rotating the brackets 44 and 46 about their axes. The diameter of the opening 50 for receiving the bracket 44 is sufiiciently great to permit passage of the roll [4 axially therethrough. The construction and mounting of the rolls l6 and I8 are the same so that description of one will suffice. Each of the rolls [6 and I8 is mounted on a shaft 52 which is supported in a bracket 54 mounted on the vertical arm 56 of a two-arm lever 58 which is pivotally mounted on a pin 60. The other arm ,62 of the lever is provided with a counterweight 64, the position of which may be varied to obtain the desired tension in the belt passing over the associated roll. Shaft 52 is in threaded engagement with the bracket 54 and is provided with a hand wheel 66 at its outer end so that it may be easily adjusted axially. A second hand wheel 68 is threaded on the shaft 52 and serves to lock the shaft in adjusted axial position. The bracket 54 is mounted for pivotal movement around a bolt 10 and is held in position on top of the arm 56 by means of bolts 12 which pass downwardly through slots 14 in the bracket and are threaded into the arm 56. The roll 20 consists of two frusto-conical portions rotatably mounted on a bent shaft 16 having one end supported by the vertical arm 18 of a twoarm lever 80 which is pivotally mounted on a pin 82. The horizontal arm 84 of lever 86 supports a counterweight 86 which is adjustably mounted thereon. The mounting for the twobelt system is the same as for the three-belt system except that the self-centering roll 20 is omitted. In placing the belts B-3, B-4 and 13-5 on their respective rolls the rolls I6, [8 and 20 are moved toward the roll 12 and the belts 13-3, B-4 and B- are placed successively over the wall 26 and around the rolls l2, l4, l6, l8 and 20. The rolls I 6 and [8 are moved in the desired transverse position by means of the hand wheels 66 and held in adjusted position by means of lock nuts 68. The angular position of the rolls l6 and I8 is adjusted by loosening the bolts and I2 and moving the bracket 54 about the pivot bolt 10 after which the bolts 10 and 12 are tightened. The positions of the counterweights 64 and 86 are adjusted in order to provide the required tension on the belts 13-3, B-4 and B-5. Belt tension may be provided by means of an air cylinder instead of in the manner shown.

Any number of belts may be used by utilizing the two systems described above. When using an even number of belts start with the two-belt system and add pairs of belts each similar to the basic pair. For odd numbers of belts start with 4 the three-belt system and add pairs of belts each similar to the two-belt basic pair.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

We claim:

1. Apparatus for tracking multiple endless belts comprising a self-centering roll over which said belts pass in side by side relationship, and two opposed frusto-conical rolls spaced from said self-centering roll arranged with their large diameter ends facing each other, the axes of said frusto-conical rolls converging toward each other and away from the self-centering roll, one of said belts passing around each of said frustoconical rolls.

2. Apparatus for tracking multiple endless belts according to claim 1 including means for adjusting said frusto-conical rolls toward and away from each other, means for changing the angular arrangement of said frusto-conical rolls, and means for changing the distance between said frusto-conical rolls and said self-centering roll.

3. Apparatus for tracking multiple endless belts according to claim 1 including a second self-centering roll spaced from the first self-centering roll around which one of said belts passes, said second self-centering roll bein located between said frusto-conical rolls.

4. Apparatus for tracking multiple endless belts according to claim 3 including means for adjusting said frusto-conical rolls toward and away from each other, means for changing the angular arrangement of said frusto-conical rolls, and means for changing the distance between said frusto-conical rolls and said first self-centering roll.

5. An abrading machine comprising a plurality of endless abrasive belts, a cylindrical work roll around which said belts pass in abutting relationship, a self-centering roll over which said belts pass arranged adjacent saidwork roll on the approach side thereof, and two opposed frustoconical rolls spaced from said self-centering roll arranged with their large diameter ends facing each other, said self-centering roll being arranged between said work roll and said frustoconical rolls, the axes of said frusto-conical rolls converging toward each other and away from the self-centering roll, one of said belts passing around each of said frusto-conical rolls.

6. An abrading machine according to claim 5 including means for adjusting said frusto-conical rolls toward and away from each other, means for changing the angular arrangement of said frusto-conical rolls, and means for changing the distance between said frusto-conical rolls and said self-centering roll.

7. An abrading machine according to claim 5 including a second self-centering roll spaced from the first self-centering roll around which one of said belts passes, said second self-centering roll being located between said frusto-conical rolls.

AII abrading machine according to claim 7 including means for adjusting said frusto-conical rolls toward and away from each other, means for changing the angular arrangement of saidfrusto-conical rolls, and means for changing the distance between said frusto-conical rolls and said first self-centering roll.

No references cited. 

